EP0187864A1 - Systeme de commande d'acceleration/deceleration - Google Patents
Systeme de commande d'acceleration/deceleration Download PDFInfo
- Publication number
- EP0187864A1 EP0187864A1 EP85903379A EP85903379A EP0187864A1 EP 0187864 A1 EP0187864 A1 EP 0187864A1 EP 85903379 A EP85903379 A EP 85903379A EP 85903379 A EP85903379 A EP 85903379A EP 0187864 A1 EP0187864 A1 EP 0187864A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- deceleration
- acceleration
- circuit
- linear
- exponential
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
- G05B19/416—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by control of velocity, acceleration or deceleration
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/34—Director, elements to supervisory
- G05B2219/34042—Filter
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/43—Speed, acceleration, deceleration control ADC
- G05B2219/43048—Step change in reference, soft start, smoothing reference
Definitions
- the present invention relates to an acceleration and deceleration system, and more particularly to an acceleration and deceleration system for an electric motor employed to drive a movable member of a machine tool, a robot hand, or the like.
- Movable members of machine tools, robot hands, or the like are generally driven by electric motors such as servomotors.
- the electric motor When driving a movable member of a machine tool or moving a robot hand, the electric motor is generally accelerated or decelerated so as not to apply a shock or vibration to the mechanical system at the time the motor starts to rotate or is stopped.
- As one acceleration and deceleration system there is known a system for exponentially increasing or decreasing the rate of a pulse for controlling the servomotor, as shown in FIG. 5.
- the acceleration and deceleration control may be carried out entirely irrespectively of interpolation, and if interpolation is simply started, acceleration is caused, whereas if interpolation is finished, deceleration results.
- the exponential acceleration and deceleration system is advantageous in that the interpolator and the acceleration and deceleration circuit are simple in arrangement. Since, however, this system involves an inherent lag upon acceleration and deceleration, the lags of the axes cannot be equalized in circular interpolation under two-axis control, resulting in a disadvantage in that a path after acceleration and deceleration is subjected to an error.
- the linear acceleration and deceleration system is problematic in that the controlled speed is not smooth and is subject to abrupt changes as compared with the exponential acceleration and deceleration control, and the mechanical system suffers shocks or vibration as the speed goes through the abrupt changes when an axis starts moving or is decelerated.
- the present invention has been made in an effort to solve the above problem. It is an object of the present invention to provide an acceleration and deceleration system capable of smoothly and accurately driving a mechanical system.
- an acceleration and deceleration system for progressively increasing a feed speed up to a command speed and progressively reducing the feed speed, comprising a linear acceleration and deceleration circuit for receiving data based on a feed speed signal and a displacement signal and effecting a linear acceleration and deceleration computation on the received signals, and an exponential acceleration and deceleration circuit for receiving an output signal from the linear acceleration and deceleration circuit and effecting an exponential acceleration and deceleration computation on the received signal.
- acceleration and deceleration system of the invention abrupt changes in the controlled speed which are the disadvantage of the linear acceleration and deceleration circuit are reduced by the exponential acceleration and deceleration circuit to prevent shocks from being produced when an axis starts moving and is decelerated and to perform smooth and accurate acceleration and deceleration control.
- Fig. 1 is a block diagram of an acceleration and deceleration control system according to the present invention
- Fig. 2 is a block diagram of a linear acceleration and deceleration circuit
- Fig. 3 is a diagram showing operating characteristics of the linear acceleration and deceleration circuit
- Fig. 4 is a block diagram of an exponential acceleration and deceleration circuit
- Fig. 5 is a diagram showing operating characteristics of the exponential acceleration and deceleration circuit
- Fig. 6 is a diagram illustrative of operating characteristics of the acceleration and deceleration system of the present invention
- Fig. 7 is a block diagram of an embodiment in which the present invention is applied to a two-axis control servo circuit.
- Fig. 1 is a block diagram explanatory of an acceleration and deceleration circuit in an acceleration and deceleration system according to the present invention.
- Denoted at 3 is a linear acceleration and deceleration circuit, and 4 an exponential acceleration and deceleration circuit.
- the linear acceleration and deceleration circuit 3 is followed by and connected in series with the exponential acceleration and deceleration circuit 4.
- a pulse distributor 5 in a servo system for example, for issuing a signal as a speed commmand is connected in series with the input terminal of the linear acceleration and deceleration circuit 3, and the output terminal of the exponential acceleration and deceleration circuit is connected to a servo circuit 6.
- a servomotor 7 is controlled by the servo circuit 6.
- the linear acceleration and deceleration circuit 3 is supplied with a signal ⁇ X as a speed command produced from the pulse distributor 5.
- the linear acceleration and deceleration circuit 3 has n (n is equal to TL/T where TL is a time constant and T is a sampling time) buffer registers #1, #2, ... #( g - 1), #n, an adder ADD, an accumulator ACC for temporarily storing the sum from the adder ADD, a register SUM for transferring the sum, and a divider DIV for dividing the sum by n.
- the buffer registers #1 through #n are connected in series. In each sampling cycle, the latest interpolation data ⁇ X is stored in the buffer register #1, and the content of each buffer register is transferred to a next buffer register, while the content AXo of the final buffer register #n is applied to the adder ADD.
- the adder ADD effects the computation: where St is the content of the register SUM, and stored the result in the accumulator ACC.
- the content of the accumulator ACC is divided by the divider DIV by n, and the quotinent is issued as pulses XP.
- the content of each buffer register #1 through #n is shifted to a next buffer register, ⁇ X is stored in the first buffer register #1, and the content St of the accumulator ACC is transferred to the register SUM.
- the linear acceleration and deceleration circuit 3 itself has acceleration and deceleration operation characteristics as shown in Fig. 3.
- the exponential acceleration and deceleration circuit 4 comprises a combination circuit 4a for combining pulses XP produced from the linear acceleration and deceleration circuit 3 and output pulses XCP from the exponential acceleration and deceleration circuit 4 itself, a register 4b for accumulating pulses issued from the combination circuit 4a, an accumulator 4c, and an adder 4d for adding the content E of the register 4b and the content of the accumulator 4c each time a pulse P of a fixed rate Fc is generated and for setting the sum in the accumulator 4c.
- the number of bits in the accumulator 4 is n.
- the output pulse speed Fo is exponentially increased at a start, and exponentially reduced at a stop as shown in Fig. 5.
- the time constant is TE
- the contant K is equal to 1/TE.
- the output terminal of the exponential acceleration and deceleration circuit 4 is connected to the servo circuit 6 to apply the output pulses XCP to the servo circuit 6.
- the servo circuit 6 is responsive to the output pulses XCP from the exponential acceleration and deceleration circuit 4 to drive the servomotor 7.
- Pulses based on data in each sampling cycle, which are issued from the pulse distributor 5, are applied to the linear acceleration and deceleration circuit 3, which then effects the linear acceleration and deceleration control as shown in Fig. 3.
- the output pulse which is subjected to the linear acceleration and deceleration control is applied to the exponential acceleration and deceleration circuit 4.
- the varying rate of the exponential acceleration and deceleration circuit 4 upon acceleration and deceleration is not abruptly changed. Therefore, as illustrated in Fig. 4, the acceleration and deceleration characteristics of the pulse XCP issued from the exponential acceleration and deceleration circuit 4 are controlled so that the angular corners of the pulse shape are rounded.
- the acceleration and deceleration system according to the present invention can shorten a positioning time by selecting the time constant ⁇ E of the exponential acceleration and deceleration circuit 4 to be small as compared with the time constant TL of the linear acceleration and deceleration circuit 3.
- Designated at 10 in Fig. 7 is an interpolator for displacement components ⁇ X, ⁇ Y in the directions of the X-and Y-axes by using a feed speed F indicated by a control signal from the numerical control apparatus (not shown), a displacement X of the X-axis, and a displacement Y of the Y-axis.
- the interpolation data signals ⁇ X, AY are applied respectively to an X-axis linear acceleration and deceleration circuit 20 and a Y-axis linear acceleration and deceleration circuit 30.
- the linear acceleration and deceleration circuits 20, 30 are identical to the linear acceleration and deceleration circuit 3 shown in Fig. 3, and operate in the same manner.
- Denoted at 40, 50 are exponential acceleration and deceleration circuits which are identical to the exponential acceleration and deceleration circuit 4 shown in Fig. 1 and operate in the same manner.
- Output pulses XCP, YCP issued from the exponential acceleration and deceleration circuits 40, 50 are applied respectively to X- and Y-axis servo circuits 60, 70, which control servo motors 80, 90, respectively, based on the applied command signals in the form of the output pulses XCP, YCP.
- the speed command signals comprising the pulses ⁇ X, 4Y issued from the interpolator 10 for the X- and Y-axis directions are controlled to have substantially the same acceleration and deceleration characteristics as shown in Fig. 3.
- Pulses XP, YP produced from the linear acceleration and deceleration circuits 20, 30 are applied to the exponential acceleration and deceleration circuits 40, 50.
- the exponential acceleration and deceleration circuits 40, 50 operate to round only angular portions of the acceleration and deceleration characteristics so that the acceleration and deceleration characteristics will not be abruptly changed when the servomotors 80, 90 are accelerated and decelerated.
- acceleration and deceleration control of an electric motor can smoothly be performed, and the motor can be driven without imposing shocks and vibration to a mechanical system.
- the present invention is preferably used in acceleration and deceleration control of electric motors for use in machine tools controlled by numerical control apparatus and robots.
Landscapes
- Engineering & Computer Science (AREA)
- Human Computer Interaction (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Numerical Control (AREA)
- Control Of Position Or Direction (AREA)
Abstract
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59138270A JPS6118009A (ja) | 1984-07-04 | 1984-07-04 | 加減速制御方式 |
JP138270/84 | 1984-07-04 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0187864A1 true EP0187864A1 (fr) | 1986-07-23 |
EP0187864A4 EP0187864A4 (fr) | 1988-11-22 |
EP0187864B1 EP0187864B1 (fr) | 1992-08-26 |
Family
ID=15217998
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP85903379A Expired EP0187864B1 (fr) | 1984-07-04 | 1985-07-04 | Systeme de commande d'acceleration/deceleration |
Country Status (5)
Country | Link |
---|---|
US (1) | US4706003A (fr) |
EP (1) | EP0187864B1 (fr) |
JP (1) | JPS6118009A (fr) |
DE (1) | DE3586563T2 (fr) |
WO (1) | WO1986000730A1 (fr) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0378708A1 (fr) * | 1988-07-28 | 1990-07-25 | Fanuc Ltd. | Dispositif de commande d'acceleration et de deceleration pour servocommande |
EP0864952A1 (fr) * | 1997-03-13 | 1998-09-16 | Dr. Johannes Heidenhain GmbH | Methode pour usiner une pièce avec une vitesse d'usinage maximale |
WO2001001556A1 (fr) * | 1999-06-28 | 2001-01-04 | Valeo Electrical Systems, Inc. | Systeme de commande du regime moteur optimal |
CN109849025A (zh) * | 2017-11-30 | 2019-06-07 | 发那科株式会社 | 振动抑制装置 |
Families Citing this family (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4829219A (en) * | 1986-11-20 | 1989-05-09 | Unimation Inc. | Multiaxis robot having improved motion control through variable acceleration/deceleration profiling |
JPS63273108A (ja) * | 1987-04-30 | 1988-11-10 | Fanuc Ltd | 速度制御装置 |
JPS6431206A (en) * | 1987-07-28 | 1989-02-01 | Amada Metrecs Co | Software servo device |
JP2707087B2 (ja) * | 1987-09-09 | 1998-01-28 | ファナック株式会社 | ロボット制御装置 |
JP2635332B2 (ja) * | 1987-09-14 | 1997-07-30 | ファナック 株式会社 | 機械加工におけるスピンドルモータと送り用サーボモータとの同期制御方法 |
JPH01164280A (ja) * | 1987-12-21 | 1989-06-28 | Fanuc Ltd | 加減速制御方式 |
DE58902651D1 (de) * | 1988-05-03 | 1992-12-17 | Siemens Ag | Verfahren zum steuern der bewegung eines maschinenelementes. |
JPH0277903A (ja) * | 1988-09-14 | 1990-03-19 | Fanuc Ltd | 数値制御方法 |
US5055761A (en) * | 1989-02-21 | 1991-10-08 | Linear Instruments | Smooth rotation by a galvanometer |
JPH02259911A (ja) * | 1989-03-31 | 1990-10-22 | Nippei Toyama Corp | 数値制御装置 |
KR900017735A (ko) * | 1989-05-19 | 1990-12-19 | 강진구 | 이송물의 직선 이송방법 |
JPH03281083A (ja) * | 1990-03-29 | 1991-12-11 | Fanuc Ltd | Cncレーザ加工機の姿勢制御方式 |
EP0477412A1 (fr) * | 1990-09-27 | 1992-04-01 | Siemens Aktiengesellschaft | Procédé pour filtrage de signaux digitaux |
US5396160A (en) * | 1991-03-11 | 1995-03-07 | General Motors Corporation | Method of real-time machine path planning from a math model |
JP3083870B2 (ja) * | 1991-05-10 | 2000-09-04 | ファナック株式会社 | 数値制御装置 |
JP3248008B2 (ja) * | 1992-09-25 | 2002-01-21 | 三信工業株式会社 | 船外機の排気浄化用触媒支持構造 |
JP2862052B2 (ja) * | 1993-04-01 | 1999-02-24 | 三菱電機株式会社 | 位置指令方法及びその装置 |
JP3046177B2 (ja) * | 1993-05-10 | 2000-05-29 | オークマ株式会社 | 加減速制御装置 |
US5434489A (en) * | 1993-07-30 | 1995-07-18 | Fanuc Robotics North America, Inc. | Method and system for path planning in cartesian space |
US5740327A (en) * | 1994-12-27 | 1998-04-14 | Nec Corporation | Method of and apparatus for robot tip trajectory control |
JP3000889B2 (ja) * | 1995-06-13 | 2000-01-17 | ダイキン工業株式会社 | ロボットの軌跡制御方法 |
JP3673383B2 (ja) * | 1997-12-12 | 2005-07-20 | ファナック株式会社 | ロボットの制御装置 |
JP2001086798A (ja) * | 1999-09-16 | 2001-03-30 | Fuji Photo Optical Co Ltd | モータの制御方法及び装置 |
DE10002563A1 (de) * | 2000-01-21 | 2001-08-02 | Siemens Ag | Verfahren zum Steuern des Hochlaufs eines Förderbandes und Antriebseinrichtung für ein Förderband |
JP2004152119A (ja) * | 2002-10-31 | 2004-05-27 | Yaskawa Electric Corp | マシンコントローラのフィルタ |
JP4569372B2 (ja) * | 2005-05-09 | 2010-10-27 | トヨタ自動車株式会社 | モータ制御装置 |
JP2020106006A (ja) | 2018-12-28 | 2020-07-09 | 本田技研工業株式会社 | 排気浄化構造及び船外機 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3512066A (en) * | 1967-03-08 | 1970-05-12 | Gerber Scientific Instr Co | Motor energizing system |
EP0139010A1 (fr) * | 1983-03-16 | 1985-05-02 | Fanuc Ltd. | Procede de regulation d'acceleration et de deceleration |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4846778A (fr) * | 1971-10-18 | 1973-07-03 | ||
JPS5246356B2 (fr) * | 1972-08-12 | 1977-11-24 | ||
JPS5234184A (en) * | 1975-09-10 | 1977-03-15 | Fanuc Ltd | Servo-system driving method |
JPS5422078A (en) * | 1977-07-20 | 1979-02-19 | Toyo Electric Mfg Co Ltd | Command circuit |
JPS5633703A (en) * | 1979-08-25 | 1981-04-04 | Fanuc Ltd | Signal converting circuit |
JPS5962909A (ja) * | 1982-10-01 | 1984-04-10 | Fanuc Ltd | 加減速装置 |
-
1984
- 1984-07-04 JP JP59138270A patent/JPS6118009A/ja active Pending
-
1985
- 1985-07-04 WO PCT/JP1985/000377 patent/WO1986000730A1/fr active IP Right Grant
- 1985-07-04 DE DE8585903379T patent/DE3586563T2/de not_active Expired - Fee Related
- 1985-07-04 EP EP85903379A patent/EP0187864B1/fr not_active Expired
- 1985-07-04 US US06/843,694 patent/US4706003A/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3512066A (en) * | 1967-03-08 | 1970-05-12 | Gerber Scientific Instr Co | Motor energizing system |
EP0139010A1 (fr) * | 1983-03-16 | 1985-05-02 | Fanuc Ltd. | Procede de regulation d'acceleration et de deceleration |
Non-Patent Citations (1)
Title |
---|
See also references of WO8600730A1 * |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0378708A1 (fr) * | 1988-07-28 | 1990-07-25 | Fanuc Ltd. | Dispositif de commande d'acceleration et de deceleration pour servocommande |
EP0378708A4 (en) * | 1988-07-28 | 1992-03-11 | Fanuc Ltd | Apparatus for controlling acceleration and deceleration for servo control |
EP0864952A1 (fr) * | 1997-03-13 | 1998-09-16 | Dr. Johannes Heidenhain GmbH | Methode pour usiner une pièce avec une vitesse d'usinage maximale |
US6249097B1 (en) | 1997-11-21 | 2001-06-19 | Valeo Electrical Systems, Inc. | Optimum motor speed control system |
WO2001001556A1 (fr) * | 1999-06-28 | 2001-01-04 | Valeo Electrical Systems, Inc. | Systeme de commande du regime moteur optimal |
CN109849025A (zh) * | 2017-11-30 | 2019-06-07 | 发那科株式会社 | 振动抑制装置 |
CN109849025B (zh) * | 2017-11-30 | 2021-01-15 | 发那科株式会社 | 振动抑制装置 |
US10940585B2 (en) | 2017-11-30 | 2021-03-09 | Fanuc Corporation | Vibration suppression device |
Also Published As
Publication number | Publication date |
---|---|
DE3586563T2 (de) | 1993-02-25 |
US4706003A (en) | 1987-11-10 |
EP0187864A4 (fr) | 1988-11-22 |
WO1986000730A1 (fr) | 1986-01-30 |
JPS6118009A (ja) | 1986-01-25 |
DE3586563D1 (de) | 1992-10-01 |
EP0187864B1 (fr) | 1992-08-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0187864A1 (fr) | Systeme de commande d'acceleration/deceleration | |
US4554497A (en) | Acceleration/deceleration circuit | |
JPS59177604A (ja) | 数値制御方法 | |
EP0077178B1 (fr) | Système de régulation de moteur pour fonctionnement en synchronisme | |
EP0378708A1 (fr) | Dispositif de commande d'acceleration et de deceleration pour servocommande | |
US5004968A (en) | Method for acceleration and deceleration control of servomotors | |
EP0329080A2 (fr) | Dispositif de commande numérique pour usiner des pièces non circulaires | |
EP0062075B1 (fr) | Systeme de commande numerique | |
EP0299080B1 (fr) | Regulateur de vitesse dans un servosysteme | |
JPS63273108A (ja) | 速度制御装置 | |
US4386407A (en) | Lathe control system | |
EP0851328B1 (fr) | Procede de commande par superposition utilisant un dispositif de commande numerique | |
EP0364593B1 (fr) | Machine-outil pourvue de deux broches principales | |
US6999844B2 (en) | Numerical controller | |
EP0072870A1 (fr) | Systeme de rattrapage de jeu pour systemes de commande a retroaction a deux positions | |
US3731175A (en) | Servo system for velocity and position control | |
US3783719A (en) | Machine tool | |
JPS60209812A (ja) | 加減速制御方式 | |
JP3136851B2 (ja) | ねじ加工装置 | |
JP2819411B2 (ja) | 定位置停止制御装置 | |
JPS61245209A (ja) | 加減速制御方式 | |
JPS63157209A (ja) | 数値制御工作機械の送り制御方法および送り制御装置 | |
JPH044405A (ja) | 数値制御装置 | |
JPH0695720A (ja) | 数値制御方式 | |
JPS61131004A (ja) | 加減速制御方式 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19860320 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE FR GB |
|
A4 | Supplementary search report drawn up and despatched |
Effective date: 19881122 |
|
17Q | First examination report despatched |
Effective date: 19900601 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE FR GB |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19920826 |
|
REF | Corresponds to: |
Ref document number: 3586563 Country of ref document: DE Date of ref document: 19921001 |
|
EN | Fr: translation not filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19930704 |
|
26N | No opposition filed | ||
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19930704 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20000703 Year of fee payment: 16 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20020501 |